What to price images at?!

Hello.
I'm having difficulty putting a price on something that i've been commissioned to do. Basically i work in a restaurant and it's being refirbished soon and i have been asked to come get around 10 images of the surrounding countryside (the brief is: 'Bring the outside in"). An example of the type of photo can be found below.
The guy who's designing the place has asked for only scans from negatives, not actual prints unfortunately, and he said in his e-mail "How much would you be looking for for each image?". I haven't a clue as this is the first time something of mine is going to be 'sold'.
So baring in mind all im giving him are high quality scans from negs, how much should i say?! £5 a image? £75?!